Glutamine is an amino acid which is rapidly depleted in critical illness. It is used as energy by cells that line the gut, vital for immune system function, and works as an anti-oxidant. Glutamine supplementation has been shown to improve outcomes in ICU patients. We hypothesize that critically ill patients given extra glutamine will have less of an inflammatory response and therefore better outcomes than patients not given extra glutamine. Our study randomizes patients to tube feeding with OR without extra glutamine to see if it affects patient outcomes as well as markers of inflammation.